1. Field of the Invention
The present invention relates to a load driving circuit, and in particular, to protection technology therefor.
2. Description of the Related Art
A load driving circuit which supplies a drive current or a drive voltage to a load is used in many electronic circuits, such as motor drivers, switching power supplies, and output stages of operational amplifiers. The load driving circuit in general performs push-pull operations, that is, an operation of “pushing” a current to a load, or an operation of “pulling” a current from a load. The load driving circuit includes a high side transistor and a low side transistor connected in series between two fixed voltages, for example, a power supply voltage and a ground voltage, and a connection point of the two transistors is connected to the load, as an output terminal.
In such a load driving circuit if the output terminal is grounded or is connected to a power supply line, there is a risk of an overcurrent flowing in the transistors or the load that is to be driven. Consequently, a protection function, that is short-circuit protection or short-to-supply protection is provided. Related technology is described in Patent Document 1.    Patent Document 1: Japanese Patent Application, Laid-Open No. H8-097640